Part 2: Usability

By Ben Ellison — March 2003

Then there's the opposite of bright colors: dimming the display for night running. The brightness of all the machines I tested went low enough to comfortably view even in pitch-black conditions, but many could use more increments between full bright and full dim. The Raymarine RC530, with its 100 easily adjusted steps and clever button lighting, was the benchmark in this department, as it was in many areas of display. Several of the plotters also offer color palate choices, which is one of the many features that come along with C-Map's NT+ chart format, a subject worthy of digression.

It's important to know that the same C-Map chart cartridge does not necessarily look the same or have the same options available from one plotter to another. C-Map produces the chart data and has specified all sorts of things that can be done with it, but the machine designers have a lot to do with the end result. Thus, for instance, the default amount of chart detail shown at a given zoom level--important to viewability--varies, as does user control of this detail. And, while most of my test units use C-Map, there's a similar flexibility to the relationship between plotters and Navionics, a company we'll likely be hearing a lot about in 2003. Navionics is right now introducing its Gold chart format whose presentation features will compete directly with C-Map's NT+ (and Garmin's proprietary BlueCharts). We'll soon see how Gold looks on a bevy of new plotters from Magellan, Lowrance, and others.

USABILITY
Chartplotters demand lots of attention from your fingers as well as your eyes, and designers have come up with diverse schemes to help you move around on your charts, switch display screens, and access the ever-increasing number of options. Among the test group, for example, there were three kinds of cursor controls: rocker switch, shuttle stick, and track ball. I didn't develop a preference for any particular type, but I did appreciate ones that were especially smooth and directionally accurate. I also liked the button grouping on the Navman (as well as Simrad's 33 series), which lets your hand rest steady while your thumb does the work, although the feature is decidedly less important on steadier boats than mine.

When moving around a chart you'll appreciate what's called a context sensitive cursor (i.e. some visual sign that you've touched an underlying navigation aid, waypoint, etc.) and knowing that specific added information or commands are available (usually with the Enter key). In some cases, as in the Si-Tex photo, a data window will pop up on its own. This idea is executed in numerous ways, none perfect in my judgment, but many useful. It can also work for functions besides the cursor. For instance, the first press of Garmin's Menu key brings up a small selection of options pertinent to whatever screen or field is selected, while the second press calls up the master menu system. Similarly, holding down one of Standard's or Si-Tex's softkeys lets you select which screen that key will shortcut to. This can save you a lot of time.